The present invention relates to an improvement in an electronic cash register which can count the number of customers who purchase a particular commodity or item on sale and, more particularly, an electronic cash register which has a function to determine a correlation between a specific item on sale and a factor associated therewith, such as another item or hour of the day.
A conventional electronic cash register is known to count the number of customers who purchase items classified into categories. This register counts the number of customers in the following manner. The register has a counter for each category of items. When a customer purchases an item, the corresponding counter is incremented by 1 so that the total number of customers who purchase items of this category can be determined.
However, in such a conventional electronic cash register, the number of customers for each category of items is independently produced when stored data is looked up. This means that the total number of customers who purchase a particular item cannot be determined. It is impossible to determine the number of customers who purchase two particular items, or either of such two particular items. In other words, a correlation between the number of customers who purchase different items, or the number of customers who purchase a particular item at a specific hour cannot be determined. For this reason, associated items cannot be effectively displayed or advertised, and the item display cannot be appropriately changed in accordance with hours.